Re: [EXTERNAL] Re: unable to get virtual serial console for EFI

From: Warner Losh <imp_at_bsdimp.com>
Date: Tue, 24 May 2022 16:07:35 UTC 
On Tue, May 24, 2022, 9:53 AM Souradeep Chakrabarti <
schakrabarti@microsoft.com> wrote:

> Hi Warner,
>
>
>
> The ConOut is :
>
>
>
> global NV,BS,RS ConOut =
> AcpiEx(VMBus,,)/VenHw(9B17E5A2-0891-42DD-B653-80B5C22809BA,02780ADA77E3AC4A8E770558EB1073F8C7E020566280CE4DAEB7520C7EF76171)
>
And what does dmesg say?

Warner


Regards,
>
> Souradeep
>
>
>
> *From:* Warner Losh <imp@bsdimp.com>
> *Sent:* Tuesday, May 24, 2022 8:23 PM
> *To:* Souradeep Chakrabarti <schakrabarti@microsoft.com>
> *Cc:* arm@freebsd.org; Wei Hu <weh@microsoft.com>
> *Subject:* [EXTERNAL] Re: unable to get virtual serial console for EFI
>
>
>
> You don't often get email from imp@bsdimp.com. Learn why this is important
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>
> What does the ComOut variable say?
>
>
>
> Warner
>
>
>
>
>
> On Mon, May 23, 2022 at 3:57 AM Souradeep Chakrabarti <
> schakrabarti@microsoft.com> wrote:
>
> Hi,
>
> I am trying to get the virtual serial console to access via putty while
> booting FreeBSD 13 arm64 bootonly on Hyper-V.
>
>
>
> Setting console="efi" is not helping to have the virtual serial console
> access using putty for ARM64. It is before any kernel module loaded.
>
> I can get the loader output in vmconnect.exe but not in the putty.
>
>
>
> Though I can see VM is getting connected to Hyper-V virtual COM1 console.
> But no output is coming to putty.
>
>
>
> I have following question :
>
> Any specific support from EFI firmware, is required for virtual serial to
> work in EFI loader in this phase of loading?
>
>
>
> I can see FreeBSD EFI loader is able to read the ConInDev and ConOutDev
> variables.
>
>
>
> With set console="efi" or set console="comconsole,efi"  or set
> console="efi" , nothing in getting redirected in putty in arm64.
>
> But in X86 that is not the problem.
>
>
>
> Without this debugging the bring up of FreeBSD on arm64 Hyper-V is quite
> difficult. Any help or pointers are really appreciated.
>
>
>
> Regards,
>
> Souradeep
>
>
>
>